Automatic telephone system



, 1,569,678 w. T. POWELL l AUTOMATIC TELEPHONE SYSTEM Filed Sept- 4, 1923 2 Sheets-Sheet 1 mvENToR WINFRED T. POWELL BY l Jan. 12 ,1926.

10.530 UZ-J Jan. v12 1926.

w. T. POWELL AUTOMATIC TELEPHONE SYSTEM Filed sept. 4, 1923 2 sheets-sheet 2l INVENToR WINFREDT. POWELL Arr NEY D n m Kokoowl-mwov. zorimom mnu-:UUEB

lPatented Jamie?, 1926i. f

iran stares WINERED T. POWEEL, OE RociTEsTER,. NEWYORR.` AssIGNoR YTo THE sTRoMiaERce paraat orwell-3.,

CARLSON TELEPHONE MAnUEneTURin-G coi/Param or RooHEsTER, NEW YORK,

A CORPORATION OE REW YORK.

AUTOMATTC TELEriToNE SYSTEM.

Application led September 4, 1923. Serial No. 66,761.

To all 107mm t may concern.'

Be it known that I, VVINFRED T. POWELL, a citizen ot the United States, residing at Rochester, in the county 'l of Monroe and State of New York, have invented certain new and useful Improvements in Automatic Telephone Systems, of which the following is a full, clear, concise, andV exact descrip` tion. 1^ l f n This invention relates to A telephone sysktenis and more particularly to telephone systems employing automatic Aswitches in completing a connection between'telephone lines.

In systems where automatic switchesare employed, it becomes necessary to provide indicating devices toindicate the failure o t certain portions of the apparatus and cir cuits. r Some4 of the diiiiculties or troubles for whichv indicating devices are provided arise from the so-called sticking of an automatic switch which prevents the advancing or releasing of said switch. Other troubles for which indicators are provided, are fuse failures and permanent signals arisingfrom the failureof a subscriber to replace his receiver on his switch-hookron the termination of a call. M

In large exchanges the difficulties shown by the indicating vdevice are corrected by one or more switchboard attendants who are always present, but incertain 01"' the branch exchanges the number lof switches are so few thata trouble manor switchboardattendant is not employed and such olices are known as unattended oiiices. When troubles of the character above mentioned arise in such an unattended, oflice,

- means must be providedto indicate at the main exchange the location and the charside by side diagrammatically represent 'a portion' of the telephone system incorporat- -ing the present invention.

At the upper left hand corner of Fig. 1 there 1s represented an automatic telephone line which terminates in the brushes of a line switch shown at the top of Fig. 1. This line switch as well as a selector switch and a repeater are shown. 1

Just below the pair of conductors ofthe located at the unattendedoiflce,

telephone line there are shown`stuck switch` alarm relays. In an automaticv telephone system, `it is the practice to provide a com# mon relay for each group of selector switches, which relay is energized when any of the 'selector' switches of its group are operated. The relays of three such selector switch groups are indicated."4 In connection with each lselector group there is also provided a fuse alarm relay,

such a relay isactuated when any of the' 'fuses of a group of switches has failed. `Three such fuse alarm relays are shown.

One `permanent signal relay isyalso shown.

In a commercial automfatic telephonev system such a permanent signal relay isV actuated whenever any o't' the -iirst `selector switches of a group has lbeen seized by the line switch and the seized selectoris not failed to hang up his receiver. n

At the lower portionot Fig. l there is represented a so-called sender which is ar'- ranged to send vdirective impulses automatically to the distant station such as a wire chies position' and a trunk finder which operates to connect such a sender to an'idle,

trunk leading to the distant oiiice. At the top of Fig. 2 there yis shown a trunk circuit leading from'fthe unattended otliceto the mainy exchange; two selector switches are alsoy shown at the top of this igure, which switches are arranged to be directively operated to extend the mentioned trunk to the l wire chieis position, or in theV case of regular calls, serve'to complete links in the conversational circuit. It will be understood that in a commercial exchange', instead of having'v two selectors in' a connection las in-l rheatedl in Fig. 2; line switch as well assubsequently operated by the dial impulse sender, indicating that the subscriberhas 47 is energized through its high. resistance v:waarna Y tion of the sender transmits-one directive impulse to mechanism (not shown) of the selector whose brushes are indicated at 15, l6'and` 17. In accordance with the well known operation, these brushes advance one step in their primary direction. Thereafter the selector operates automatically to select a trunk .leading to a second selector whose brushes, located at the distantoflice, are designated 5 0, 51 and 52. The brushes of the, sender switch remain in position15 for av short interval during which a circuit is closed'` from grounded battery, winding, back contact. and armature of the motor magnet 33, conductor 38, brush 37 in its fifth position through the high resistance winding of relay 47 to ground. The motor magnet is not operated owing to the high resistance of relay 47 but this relay is actuated and at its back contactand armature opens the c1rcuit which normally holds the relay 48 en .ergized- This relay is slow to release but shortly after the opening of its circuit it deenergizes and in turn eifects `the release of the normally operated 'slow releasingrelay 49. These two slow relays measure an yinterval suflicient kto vpermit the trunk hunting operation of the first selector switch at the distant o-fHce. This time interval corresponds to the interval between successive seriesv of impulses transmitted by theordinary dial impulsesender. VVhenhowever, the relay 49 deenergizes it closes a circuit from ground, through its armature and back coni tact, left hand windingv of relay 47, brush thisimpulse effects theoperation of the sec-V ond selector swi-tch whose brushes are designated 50, 51 and V52. In position 9, the relay windi'nginseries with the motor'magnet 33 and again effects the deenergization of relays 48 and 49. On the release of relay' 49, the motor magnet 33 is operated in series with the low resistance winding of relay. 47 to advance the sender into position 10. At this time the second selector at the distant oiiiee huntsy automatically for a trunk leading to the lwire chiefs position and since the sender is standing with its brushes in position 10,'a circuit is closed from groundedbattery, winding of relay 53,- sender brush 36, linderbrush 29, conductor 42. selector brushes 15and 50, contactsr 40 of theauxil.- iary answering jkey, .winding of relay 39 to ground.

The red lamp 54, which is a trouble lamp located at the wirechiefs position is now lighted in a circuit from grounded battery,

lamp 54, back Contact andarmature ofrelay 46, righthand front contact and. armature ofrelay 39,'b`a`clr contact and armature Lof slow releasing relay `55 to ground.V Since the trouble lamp 54 is thus lighted, the wire chief knows that he should operate the auxiliaiy answering key, which opens the cir-- cuit of relay 39 to disconnect the relays :39 and 46 from the signaling circuit. vIt should be statedthat the auxiliary answering key is of such dcsignthat 1t Iirstzconnects ground to Vone impulse spring -ofjt-he dialgenerally designated 56 andthenv connects kthe other impulse spring thereof tol the lower side of f the .signaling circuit before this conductor is .disconnected from the relay 46. This ar rangement insures that the relay y53 at the sender 'will not be prematurely released to advance the sender switch of Fig. 1.

The wire chief is then instructed to op.V

erate the dial sender 56 at his position to ,i

transmit a large number of impulses, preff erably ten, which operate the relay 53 of Fig.l 1. As the relay 53 vibratesit's armature, it operates the slow releasing relay57 and then closes an actuating circuit from grounded battery, winding of the motor magnet 33, front contact and. armatureof relay 57, back contact and armature of relay 53, brush 34, conductors58 and 32 back oon-y ytact and armature'of relay 31 to ground.

In response to each ofthe impulses trans mitted by the dial sender 56, the motor'm'ag? net 33 advances the brushes of thesender so that the test brush 35 can successivelytest L thc'group of alarm relays shown near the top of Fig. 1.l

circuits is operated so thatV whilev test brush 351s advancing through position 11,.a circuit vis closed from ground, armature and front contact of relay 18, brush 35, `conduci tor 43, finder brush 27 ,conductor 44, lower front contact and armature of relay 41, se`

lector brushes 16 'and 51, contacts. 58, conducn It has been assumed that the relay v18 associated with the vfirst groupl of'lo tor 59, contacts 60, conductor 61,brush`62, l i

winding of relay 63l`to grounded battery. The relay 6'3-isthus operated and is locked" in this condition from grounded battery,

windingl of relay`63, its front contact andv armature, conductor 65, front contactfand `I armature of relay 64, which relay is operated over conductor 96 when theauxiliary y"an-- sweringlrey is closed. In response'to'the remaining impulses of this series, the brushes 35 is standing in position 20. l It will be understood that, if certain of of the sender vare advanced until the brush the other trouble indicating relays such as G7 or oie. Fig. l `are actuated to indicate an abnori'nal condition, when the sender switch ot Fig. l and the receiver switch ci' Fig. are advanced,'corresponding relays (S3 and 7() are actuated to lig-ht lamps 7l and 72 in the Wire chiet'ls position. From the operation ot the lan'ips 66, 71er 72 the wire ehicit can tell the character of the trouble that exists at the unattended vottici-i indicated in Fig. l and he is alsoable to tell in. what group the trouble is located and in certain cases he can remedy the trouble Without sending trouble man out to the unattended o'iiice.

Since the lamp 66 is operated it indicates that one et the switches in the lirst group is"stuckl and it is often possible to release such a stuck7 switch by momentarily opening its battery circuit. ln order to do this it is only necessary ior the wire chief to operate the dial sender G to send one, two or three impulses, depending upon whether it is the iirst, secqnd or third `group et switches in which i the stuck switchis located. Since it has been assumed that the stuck switch is in the tirst group, theI wire chief operates his dial sender 56 to transmit one impulse. rllhis is eitective in the manner already indicated tooperate the relay53 ot Fig. l which in turn advances the sender switch now standing in position Q0 into position 21.` Y i The wire chief now closes the contacts 73 oi? the key located at his position and thereby coinpletes a circuit from ground, contacts 73, conductor 59, contact 58, selector brushes 51 and 116, lower armature and front contact et relay 41, conductor est, trunk finder brush .27,- conductor i3, `brush 35 in its t\\'enty-ii1'st position, winding of relay 74, lower winding et relay 19 to grounded battery. The relay 74' is thus operated and opens the battery lead extending through group relay 18 to the various magnets Vassociated with the stuck switch. This mocentary operation ot relay Tl and the consequent removal of battery from the stuck switch usually effects its release.

Incase some' other kind of trouble exists at the unattended ottice suchV as a fuse alarm arising trom the itailureloi a fuse, or a permanent signal alarm in which cases it is necessary to send a trouble man to the unattended oiiice, the wire chief again operates his dial sender 56 to transmit a series ot impulses, preferably which advance the sender switch ot Fig. l into posi` tion 25. It does not require l() impulses to accomplish thislast operation, butthis num her et impulses, irrespective of the position in which the senderwas standing will step it to position and no farther because in this position the impulse circuit `for relay 53" is open at brush 34.`

The wire chief may now leave the key contact 73 closed and restore the auxiliary answering key to its normal position, Vwhich is an indication that the service observing operation of this trunk has beentaken `care oi. Relay 39 is now operated in series i" 'tn the relay 53 and the red lamp Vitis now lighted ina circuit traceable from grounded battery, through the lamp 54, right hand liront contact and armature otrelay 59, cond uctor 59, contacts 73 to ground. This lamp remains lighted until the trouble at the distant otlice has been corrected when it will be extinguished and all the circuits will be restored to their normal condition.

ln the present disclosure the sender oi Fig. l is arranged to send code impulses correspondingl to #il toactuate the selec tors leading to the wire chiefs position.` It it were* desiredto send impulses correspend` ing to #21, `the conductor leading from relay T to point 5 would be remoyedand a similar conductor is connected to point 13 ot the switch bank engaged by brush 37.` The first thirteenterminals oill the various banks of the sender switch are also changed in a manner obvious 'frointhepresent ar rangement et the Iirst `ten setsot terminals ot the sender. What is claimed is: g

l. In a telephone system, a primary oiiic, a second office, means including several kinds ot apparatus at said primaryrotlice, one or more trunkl circuits extending between* said oilices, an attendants position at saidseco'nd office, means including directively operable switches and link circuits for extending a trunk to said attendants` position, an impulse sender, means responsive to the faulty operation of any ot said apparatus `*tor connecting said sender to one of saidtrunk circuits, means directively controlled from said impiiil'sesender for operating said switches to extend said trunk circuit through said link circuits `to sai'd attendants position, and

means for signaling the kind of fault-y apparatus over said established connection;

2. In a telephonesystem, a prnnaryetce,

a second oiiice, means including several kinds more trunk circuits extendingbetween` said of apparatus at said primaryoffice, one or otiices, an attendantfs position at said second oiiice, means including directively operable switches and link vcircuits for extending' a trunk to said" position, an impulse sender, means responsiveto the faulty operation of any et said apparatus for connecting said sender to one et `said trunk circuits, means directively y controlled from said impulse sender for `operating said switchesfto establislr a connection from said trunk circuit through said link circuits to said attendants position, and means for signalling the kind ot'taulty apparatusl and' the location of the same over said established connection,

tively operating said automatic switches, ak

receiver switch also located at said second oiiice, means including a dial sender for causing the `Asender lswitch at the. primary oiiice and the receiver switch at the second oiice to advance. progressively until theV group of faulty apparatus is located, and means'responsive to such operation ofsaid receiver switch for variably operating saidsignaling means.

4;. In a telephone system, a primary office, a second office means including several kinds ofl apparatus at said primary office, one or more trunk circuits extending between said oiiices, an attendants position at said second oiiice, means including directively operable switches and link circuits for extending a trunk circuit to said position, an impulse sender, means responsive tothe faulty operation of any of said apparatus for connecting said impulse sender to one of said trunk circuits and for initiating the operation of said impulsesender, means directively controlled from said impulse sender for operating said switches to extend said trunk circuit through said link circuits to said attendants'position, means for signaling the kind of faulty apparatus and the location of the same over said established connection, and variably controlled means atsaid attendants position for correcting certain of said faulty apparatus located at said iirst otlice. i

5. In a telephone system, a primary oiiice,

a second oilice, means including several kinds i of apparatus at said primary otlice, one or more trunk circuits extending between said oiiices, an attendants position at said second office, means including directively operable switches and link circuits for extending a trunk circuit to said position, an impulse sender, means responsive to the faulty operation of any of said apparatus for connecting said sender to one of said trunk circuits, means directively controlled fromsaid impulse sender for operating said switches-to establish a connection from said trunk circuit through said link circuits to said attendants position, means for signaling the? kind ofvfaulty apparatus andthe location of the same over said established connection,

and means controlled `over said connection l from said operators position for correcting certain of said faulty apparatus.

6. 'In a system of the class described,sev eral different kinds of apparat-us, an operators position, a plurality of trunks, means including directively operable switches and link circuits for extending` a trunk circuit to said position, an impulse sender, means responsive to the faulty said apparatus for connecting said impulse sender to one of said trunk circuits and for initiating the operation ot' said impulse' sender, means d irectively controlled fromv said impulse sender for operating saidV switches to 'extend said trunk circuit through said link circuits to said operators position, means at said position for signaling the kind of faulty apparatus and the location of the same over said established connection, and variably controlled means at'said operators position for correcting certain of said faulty apparatus. c

In Witness whereof, I hereunto subscribe my name this 31st day ofk August A. D. 1923. Y WINFRED T. POWELL.

operation of any of 

